[Shaelyn]

I'll add my own experience...but it's all with permanent haircolor.

my natural hair is...pretty well mixed, actually. it typically looks brown, but it's red if you catch it in the light, and it's blonde enough to turn green in chlorine. some people call it dirty blonde.

anyway. I died my hair black once - permanent. ...and it didn't come out until it grew and I cut it off. permanent damage? no. it just needed to grow.
but, that transition when it's growing back out, if you want your natural hair back, SUCKS. yours is going to be black on the bottom half, and blonde on the top...that's something to think about.

now the pink. pink and red ALWAYS FADES. no matter how permanent you get it. my second to last hair-dye job was red with black pinstripe, and my last one was all red. the recent red (this was done around June) is basically gone - my hair is slightly tinted more red than usual now...and meanwhile, those black stripes from two dye-jobs ago (which I think are from spring '06, I cut and dye my hair once a year) are still there in the longer parts of my hair. I left them because they're barely visible anyway, as a pinstripe...but I can see the black still.

that may give you an idea with how long this stuff will last, for permanent color. I've never done temporary or semi-permanent though. those should wash out slowly...and so you won't have to wait for you hair to grow. if you're thinking pink temp or semi-perm...I'd be wary, you're probably not getting your money's worth. if red perm washes out that fast...